\setmainfont{Times New Roman}
\newcommand{\timesbf}[1]{\textbf{\fontspec[Path="fonts/"]{timesbd.ttf} #1}}
\newcommand{\timesit}[1]{\textit{\fontspec[Path="fonts/"]{timesi.ttf} #1}}
\newcommand{\timesbi}[1]{\textit{\fontspec[Path="fonts/"]{timesbi.ttf} #1}}